Self-adjusting wrench



Sept. 28, 1965 B, F. wEsTBY ETAL 3,208,319

SELF"ADJUSTING WRENCH Filed Nov.. 20, 1961 5 Sheets-Sheet 1 /6 Quim-J Sept 25, 1955 B. F. WESTBY ETAL 3,208,319

SELF-ADJUSTING WRENCH Filed Nov. 20. 1961 3 Sheets-Sheet 2 FICE. S

70d BYSmA/z-M. aua/wou 55 .FIE'L .E l g rrakw s Sept- 28, 1965 B. F. wEsTBY ETAL 3,208,319

SELF-ADJUSTING WRENCH Filed Nov. 20, 1961 3 Sheets-Sheet I5 INVENTORS Btn/jam fwn-ray BY .52m/syl M11/Anson Unite f States This invention relates to improvements in a self adjusting wrench of a type having a pivoted jaw and being sometimes referred to as locking pliers. Wrenches ot the type of the invention herein relates to and are of the type used in connection with smaller hand held work pieces wherein the locking mechanism of the device relieves the operator of the necessity for manually exerting the clamping pressure necessary to hold the work piece.

Devices of the class indicated in general are equipped with manually operable means for determining the extent to which the jaws of the device are opened and which means may require the use of both hands for adjustment including in an unnatural holding position the hand which would otherwise be holding the device in operating position. Applicants device provides for an automatic opening of the jaws to the full extent thereof. Applicants device provides further improvement in means for adjusting clamping pressure to certain dierent degrees for the same extent of jaw opening, with the adjustment being made with the hand holding the device being in its natural holding position. Also applicants device provides an unusual improvement in the form of compressible linkage for further adjustment in the clamping pressure exerted.

It is an object of this invention therefore to provide a wrench of the type indicated having a fully automatic opening of the jaws to their full extent of separation.

It is another object of this invention to provide a wrench constructed to have means for automatic adjustment of the jaws to accommodate any particular work piece and providing for the exertion of clamping pressure upon the engagement of the Work piece by said jaws.

It is also an object of this invention to provide for an adjustment of the application of clamping pressure to certain different degrees of pressure for a given work piece by the use of the hand holding the Wrench without removal of the hand from its normal operating position.

It is a further object of this invention to embody compressible linkage for an automatic adjustment or adaptation of clamping pressure to a particular work piece.

It is another object of this invention to provide means for normally urging the jaws of said wrench into a substantially pressure free engagement for the retention of a work piece therebetween during such times as clamping pressure is not applied.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughout the several views and in which:

FIG. 1 is a side view of applicants device on a reduced scale;

FIG. 2 is a view in partial vertical section showing parts of applicants device broken away and other parts in dotted line;

FIG. 3 is a fragmentary view of applicants device similar to the view in FIG. 2 with portions thereof in a different operating position, and FIG. 3A is a fragmentary view showing a detail of construction taken on line 3A-3A of FIG. 3, as indicated by the arrows;

FIG. 4 is a side view of applicants device on a somewhat reduced scale, with some portions shown in dotted line and with the device in clamping position;

` FIG. 5 is a fragmentary side view of applicants device atent ice partially in vertical section, with some parts being shown in dotted line and showing a specific operation position between portions thereof;

FIG. 6 is a View in vertical section on a somewhat enlarged scale taken on line 66 of FIG. 5, as indicated by the arrows;

FIG. 7 is a side view of a modification of applicants device;

FIG. 8 is a side view of the device partially in vertical section, with some portions being broken away and indicating a speciiic operating position between portions thereof; i

FIG. 9 is a View similar to that shown in FIG. 7, being partially in vertical lsection showing the device in clamping position;

FIG. 10 is a fragmentary View in plan and partially in section taken on line IIL-10 of FIG. 8, as indicated by the arrows;

FIG. ll is a side view of a modification of applicants device partially in vertical section, with some portions being broken away;

FIG. 12 is a fragmentary view of the device as shown in FIG. l1, with portions thereof being shown in a different operating position; and

FIG. 13 is a fragmentary view partially in plan and partially in horizontal section taken on line 13--13 of FIG. l2, as indicated by the arrows.

Referring to FIGS. 1-6, applicants device 10 is shown in various views in different operating positions. Comprising said device is a handle 12 substantially U-shaped or channel-shaped in cross section and having formed at its forward end portion a xed jaw 13 unitary therewith. Opposing said xed jaw 13 for operative association therewith is a movable jaw 15 substantially triangular in plan having a portion 15a disposed between sides: of said handle 12 to be pivotally connected thereto by a rivet 16.

An operating handle 18 channel-shaped in cross section is pivotally connected at its bifurcated end portion 18a to said jaw 15 by a rivet 20 and having a somewhat goose-necked other end portion 18b forming a hand-holding portion. A toggle linkage connects said handle 12 and said operating handle 18. Said linkage comprises a channel-shaped elongated primary link 22y having one end thereof extending into the channel of handle 18 spaced somewhat from the rivet 20 and being pivotally secured by a rivet 24. Pivoted to the other end of said link 22 by a rivet 25 is a substantially shorter secondary link 27. Said link 27 is shown having a substantially straight upper edge portion and a substantially rounded or convex lower edge portion 27a forming a cam, as viewed in the iigures.

Pivoted to the free end of said link 27 is a travel block 30. Said travel block is substantially in the form of a right angle having a bifurcated neck portion 30a pivoted to said link 27 by a rivet 31 and having a depending block-like portion 30h having a cylindrical passage 30e longitudinally therethrough. The surface of said passage may be variously treated. In the present embodiment the bottom portion of said passage is indicated as having a scored surface. Disposed in said handle 12 to extend longitudinally within the channel therein is a rod 32 indicated as being substantially cylindrical in form and being pivoted at one end portion to the rear end portion of said handle 12 by a rivet 34. Said rod will have a surface treatment to provide for a great number of points of frictional or gripping engagement with said travel block and as here presented said rod is indicated as having a transversely scored under surface portion 32a extending over a substantially rearward portion thereof. Said rod is disposed through said passage 30C of said travel block whereby an operative association is eifected between said block and the scored area of said rod.

Looped over the shank of said rivet 25 inwardly of one side of said handle 12 is a U-shaped spring 36 having one free end reversely bent over the upper edge portion of the link 27 and its other free end reversely bent oppositely of said iirst free end over the upper edge portion of the adjacent inclined end portion of the link 22 whereby normally said spring will urge said links 22 and 27 into an angular relationship which will tend to retain the pivoted portion 39a of the travel block in a substantially horizontal position to establish an operative relationship of said block to said rod 32 for a free sliding movement of said block over said rod.

Pivoted within said handle 18 rearwardly of said rivet 24 by a rivet 37 is a cam lever 38 having a neck or handle portion 38a projecting upwardly through a slot 15C in said handle and having a lower body portion 38!) having a convex lower edge portion and being substantially wedge-shaped or tapered in horizontal section widening outwardly in the direction of the lower end portion thereof, as indicated in FIG. 3A.

With particular reference to FIGS. 5 and 6, said link 22 has a U-shaped hat spring disposed therein having loop ear portions 40a extending outwardly through suitable apertures 22a at either side of said link.

Upstanding from said link 22 are a pair of transversely aligned ears 2211 forming stop members limiting the extent of the angular locking relation between the links 22 and 27 whereby the fulcrum point 2li is in locking position in an over center position just below the center line extending through the pivotal points at the points of the rivets 20 and 25.

A coiled spring 42 is disposed in the handle 12 having one end engaging an inwardly projecting tongue 12a struck from said handle and having its other end engaging a hook 15b integral with said jaw 15 outwardly of said rivet 16 whereby said spring normally urges said jaws 13 and 15 in the direction of one another just suiciently to retain a work piece 45 therebetween. Said tongue 12a also forms a stop for said travel block .30.

In operation, as the handles of applicants device are Separated to open the jaws and break the clamping grip, unlike the action which is present in the use of commonly designed similar devices where a considerable jarring or shocking effect results when the handles are snapped apart, in the applicants device the spring 42 softens and breaks the shock of snapping the handles apart so that a jarring effect is not suffered by the operator. Further the action of the spring is sufficient to make the breaking of the clamping grip and the opening of the jaws a smooth action wherein the spring retains sufcient pressure on the movable jaw to retain the work piece between the jaws so that the work piece does not pop out away from the jaws but is retained therebetween with a very slight degree of pressure.

Thus the work piece may either be changed as to its position between the jaws and reclamped or removed. With the removal of the work piece, the handles will be separated their full extent which pivots the movable jaw 15 to separate it from the jaw 13 to its fullest extent as the travel block 30 is moved forwardly on the rod 32 in the direction of the jaws. The spring 36 when the device is not in clamping position will establish an angular relationship between the link 22 and the link 27 to cause the portion 30a of the travel block to be in a substantially horizontal position so that the block will move freely axially of the rod 32.

When a work piece is to be inserted between the jaws, the operating handle 18 will be moved in the direction of the handle 12 and the travel block 3@ will move freely rearwardly of the rod 32. Upon engagement of the movable jaw 15 with the work piece a back pressure will resuit in initially causing the links 22 and 27 to come into a straight line longitudinal relationship so that in effect these two links Will become integral, the link 27 will bear against the adjacent surface of rod 32, and the portion 30a of the travel block will be tilted, as indicated in FIG.

3, whereby the point in the lower surface of the passage 30C which is nearest the jaw portions of the device will come into frictional engagement with the scored undersurface of the rod 32. Thus the travel block 3? may be locked in position relative to the rod 32 at any certain point thereon and the pivot point 24 will become the fulcrum point in exerting clamping pressure on the movable jaw 15. Said pivot point 24 will be depressed to a point just below the point of center established by a line running through the pivot points 2t? and 31. The ears 22b serve as stop members in determining the extent to which said point 24 will be depressed in its over center position. The extent to which the jaws are spread or opened by the work piece determines the angular relationship of the links 22 and 27 and the angular relationship of the link 22 and the handle 18 which relationships in turn taken together determine the distance that the block travels on the rod 32. Said block travels until the links 22 and 27 come into linear alignment or straighten suiiciently for the cam portion 27a in bearing against the rod 32 to tilt said travel block into locking engagement with said rod 32. The block is tilted to a very small extent to establish a locking engagement with the rod 32.

In the event that it may be desired to exert different degrees of clamping pressure on the Work piece than would be exerted by the normal operation of the linkage as above indicated, a cam member 38 is provided, pivoted in the handle 18 easily operable as by the thumb of the operator. The neck or handle portion 38a of said cam is moved rearwardly in the direction of the operator to bear against the adjacent ear portion 40a which heightens the angular relationship of the links 22 and 18 to lengthen the closing stroke of the movable handle without changing the opening between the jaws, in applying clamping pressure in closing the jaws, as indicated in FIG. 5. Thus the degree of clamping pressure may be readily varied to certain different degrees by the hand of the operator holding the device in its natural holding position without the need for making any manual adjustments with the non-operating hand, as would be necessary in other commonly used like devices.

Referring to FIGS. 7-10, a modiiication 50 of appli- Cants device is shown similar in appearance to said device iti and having its principal structural difference in its linkage and travel block. Said device 549 comprises a handle 52 channel-shaped in cross section having formed at its forward end a fixed jaw 53, and co-acting therewith is a movable jaw 55 pivoted to said handle by a rivet 56.

An operating handle 58 is pivotally connected at its bifurcated forward end portion 55a to said jaw 55 by a rivet 60.

The toggle linkage connecting said handle 52 and said operating handle 58 comprises an elongated flat primary link 62 having one end thereof pivoted to said handle 58 by a rivet 6d and having pivoted to its other end by a rivet 65 a secondary link 67 of relatively short length and being substantially rectangular in plan and being pivoted at its -other end by a rivet 71 to the upper bifurcated end portion a of a travel block 70. Said link 67 has a substantial concavity or wide slot 67a therein for free swinging movement through said bifurcated portion of said travel block. Said travel block has a passage 70h through which is disposed a rod 72 seated in the channel portion of said handle 52 being pivoted at its rear end portion to said handle by a rivet 7d, with the forward portion of said rod being disposed through a guide block 75 secured in said handle. The bottom surface of said rod and the adjacent surface of the passage in said travel block will be appropriately formed to have frictionally engageable surfaces. The travel block as indicated in FIG. 8 is shown being inclined forwardly relative to said rod 72 whereby frictional engagement between said travel block and said rod occurs as said block is moved in the direction of being at a right-angled relationship to said rod. Disposed about the rearward portion of said rod 72 is a coil spring 76 engaging said rivet 74 at one end and abutting said travel block 70 at its other end. Said spring will be of a length to normally urge said travel block forwardly whereby said jaws 53 and S are normally urged to a closing position. Said travel block has a portion 70a extending downwardly through a slot 521) in said handle 52, with said downwardly extending portion forming a trigger, as indicated in FIG. 7.

Upstanding on said handle 58 just forward of said rivet 64 is a boss 78 having an adjusting screw 79 threaded therethrough and through the underlying handle portion to engage the adjacent and forward convexly curved or cammed end portion 62a of said lever 62. Upstanding from said lever 62 is an ear 62h forming a stop member for association with said operating handle 58.

With reference to FIGS. 7-9, a modification of the applicants device is shown in which the jaws of the device are readily opened to their full extent by the action of the operator in drawing rearwardly the travel block 70 in a manner similar to a trigger action, as indicated in FIG. 7. Thus without the need fo any adjusting screws the jaws are opened to their full extent easily to accommodate a work piece between the jaws. When the work piece has been positioned between the jaws, the trigger portion of the travel block is released and a spring '76 urges the travel block forwardly to cause the jaws to move to closed position under a slight degree of pressure but with sufficient pressure to retain a work piece between the jaws.

The operating handle 58 is then squeezed in the direction of the handle 52. With the back pressure resulting from the engagement of the movable jaw with the work piece, the upper portion of the travel block 70 is pressed rearwardly causing a frictional engagement to result between the lower surface of the passage 7Gb through the travel block and the under surface of the rod 72. The degree of clamping pressure is readily changed to certain different degrees by action of the screw 79 which upon engagement with the forward end portion 62a of the link 62 determines its angular relationship with the forward portion of the operating handle 58. To the extent that said angular relationship becomes more acute by adjustment of the screw 79, the handle is elevated and the length of the closing stroke increases with the mouth of the jaw opening remaining unchanged and the clamping pressure thus increases. The screw 79 functions to produce a result similar to that of the cam 38 above described.

With reference to FIGS. 11-13, another modification 80 of applicants device is shown in which the same reference characters are used to indicate the portions identical with those described in connection with the device 10. The change present in this embodiment relative to the structure comprising the device has to do principally with the primary toggle link 81 being substantially the same as the link 22 in plan but is formed of solid stock, and instead of being formed of rigid material, as is the common practice, said link 81 is formed of a resilient compressible material, such as of nylon. Said link has a slot 81a at one end portion opening endwise and downwardly to pivotally receive the adjacent end portion of the link 27, the same being secured by the rivet 25. A pin 12b forms a forward stop member.

In lieu of the U spring 40, a spring loaded button 83 of conventional design is transversely recessed in said link 81, as indicated in FIG. 13, secured by a cap screw 84. Said button is engaged by the cam 28 to vary the degree of clamping pressure exerted. The device 80 is constructed to provide for a wide range of clamping pressure, not only through the compressibility of the primary link 81, but through the great number of different degrees of pressure which may result from the combination of the use of the cam 38 as above described in connection with the compressible link 81. The cam 38 will ride d on the button 83 to determine the angle between the link 22 and the forward portion of the handle 18. When the closing pressure of the handle becomes great enough, the cam will depress and overlie the projecting portion of said button.

Thus it is shown that we have provided a simply and efficiently constructed self adjusting wrench which normally provides for the opening of the jaws to their full extent and for the automatic closing of the jaws with the application of clamping pressure as determined by the size of the work piece, and with the further ready adjustment of such clamping pressure to any certain different degree which may be desired without the need for removing the operating hand from its normal operating position.

lt will of course be understood that various changes may be made in the form, details, arrangement and proportions of the parts, without departing from the scope of applicants invention which, generally stated, consists in a device capable of carrying out the objects above set forth, in the parts and combinations of parts disclosed and defined in the appended claims.

What is claimed is:

ll. A self adjusting wrench having in combination,

a handle integral with a stationary jaw,

a movable jaw pivoted to said handle coactive with said stationary jaw,

an operating handle pivoted to said movable jaw,

a rod carried in said handle lengthwise thereof,

a travel block movable axially of said rod,

a pair of pivoted toggle links respectively pivotally connected at their remote ends to said operating handle and said travel block, and

a cam portion forming the under surface on said link connected to said travel block riding; on said rod tilting said travel block into locking engagement with said rod.

2. The structure set forth in claim 1,

a cam member having an unbroken cam surface carried by said operating handle bearing against a certain point on said link connected to said operating handle adjusting the angular relationship between said last mentioned link and said operating handle to adjust the operating angle of said link and said handle in determining the clamping pressure of said jaws.

3. A self adjusting wrench having in combination,

a handle integral with a stationary jaw,

a movable jaw pivoted to said handle coactive with said stationary jaw,

an operating handle pivoted to said movable jaw,

a rod carried in said handle lengthwise thereof,

a travel block movable axially of said rod, j

a pair of pivoted toggle links respectively pivotally connected at their remote ends to said operating handle and said travel block,

a cam portion forming the undersurface on said link connected to said travel block riding on said rod tilting said travel block into locking engagement with said rod, and

means carried by said links adjacent their common pivot point releasably positioning said links relative to one another to hold 'said travel block in freely sliding relationship with said rod.

4. The structure set forth in claim 3,

said means comprising a spring member engaging adjacent portions of said links and yielding to pressure exerted by said operating handle.

References Cited by the Examiner UNITED STATES PATENTS 2,531,285 11/ 50 Manspeaker 81--379 X 2,589,511 3/52 Redmon 81--370 2,595,579 5/52 Hawkins 81--379 2,997,903 8/61 Rommel et al 81--372 X WILLIAM FELDMAN, Primary Examiner. 

1. A SELF ADJUSTING WRENCH HAVING IN COMBINATION, A HANDLE INTEGRAL WITH A STATIONARY JAW, A MOVABLE JAW PIVOTED TO SAID HANDLE COACTIVE WITH SAID STATIONARY JAW, AN OPERATING HANDLE PIVOTED TO SAID MOVABLE JAW, A ROD CARRIED IN SAID HANDLE LENGTHWISE THEREOF, A TRAVEL BLOCK MOVABLE AXIALLY OF SAID ROD, A PAIR OF PIVOTED TOGGLE LINKS RESPECTIVELY PIVOTALLY CONNECTED AT THEIR REMOTE ENDS TO SAID OPERATING HANDLE AND SAID TRAVEL BLOCK, AND A CAM PORTION FORMING THE UNDER SURFACE ON SAID LINK CONNECTED TO SAID TRAVEL BLOCK RIDING ON SAID ROD TILTING SAID TRAVEL BLOCK INTO LOCKING ENGAGEMENT WITH SAID ROD. 